Sunroofs of motor vehicles generally require shading. At practically any position of the sun, light can fall into the interior of the passenger car via the sunroof and thereby heat the interior. Roll-up sunroof shades are used to slow down the heating process. At the same time, they are able to provide light when the sunroof shade is opened.
For roll-up sunroof shades of motor vehicles, there is the problem that the deployed shade sheet sags in a basin shape due to its dead weight between the guide rails and between the pull rod and the winding shaft. One solution to counteract this sagging that has been attempted is reinforcing the blind sheet with a thin steel strip. The steel strip runs in special guide rails, which keep the shade sheet tightened in the transverse direction between the guide rails.
The expense of fastening the steel strips to the edges of the shade sheet is substantial. In addition, such a roll-up shade has the disadvantage that the roll body on the winding shaft is thicker in the area of the steel strips and increases in diameter faster there than in the area between them, which causes creasing. These creases become permanent over time and have an unpleasant appearance when the shade sheet is deployed.